a(n) = A000217(A058481(n)).

Terms

a(0) =0a(1) =1a(2) =28a(3) =325a(4) =3160a(5) =29161a(6) =264628a(7) =2388205a(8) =21513520a(9) =193680721a(10) =1743303628a(11) =15690264085a(12) =141213971080